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ARS Home » Midwest Area » St. Paul, Minnesota » Cereal Disease Lab » Research » Publications at this Location » Publication #341661

Research Project: Cereal Rust: Pathogen Biology and Host Resistance

Location: Cereal Disease Lab

Title: Adult plant leaf rust resistance derived from the soft red winter wheat cultivar Caldwell maps to chromosome 3BS

item Kolmer, James - Jim
item Chao, Shiaoman
item Brown-Guedira, Gina
item BANSAL, URMIL - University Of Sydney
item BARIANA, HARBANS - University Of Sydney

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/11/2017
Publication Date: 1/1/2018
Citation: Kolmer, J.A., Chao, S., Brown Guedira, G.L., Bansal, U., Bariana, H. 2018. Adult plant leaf rust resistance derived from the soft red winter wheat cultivar Caldwell maps to chromosome 3BS. Crop Science. 58:152-158.

Interpretive Summary: Wheat is attacked by the leaf rust fungus, Puccinia triticina. Genes in wheat can provide resistance to this important pathogen and disease of wheat. The U.S. soft red winter wheat Caldwell has had durable resistance to leaf rust since the early 1980s. A region on chromosome 3BS in Caldwell was highly associated with leaf rust resistance in genetic experiments. This region was closely located to the leaf rust resistance gene Lr74. DNA markers were developed that can be used by wheat breeders to select for germplasm with the leaf rust resistance on chromosome 3BS. The results of this research will help wheat breeders and plant pathologists to develop wheat cultivars with good long lasting resistance to leaf rust.

Technical Abstract: 'Caldwell' is a U.S. soft red winter wheat that has partial, adult plant resistance to the leaf rust pathogen Puccinia triticina. A line of 'Thatcher*2/Caldwell' with adult plant resistance derived from Caldwell was crossed with 'Thatcher' to develop a population of recombinant inbred lines (RILs). The parents and RIL population were evaluated for segregation of leaf rust resistance in four field tests. A genetic map of the RIL population was constructed using 90 K single nucleotide polymorphism (SNP) markers using the Illumina Infinium iSelect 90K wheat bead array. Significant effects for reduction of leaf rust severity in all four tests were found for a quantitative trait locus (QTL) on chromosome 3BS. Simple sequence repeat (SSR) markers linked to Lr74 and kompetitive allele specific PCR (KASP) assay markers were added to the map on chromosome 3BS. Thatcher and the resistant Thatcher*2/Caldwell parent were negative for the presence of Sr2 on chromosome 3BS based on the tightly linked marker csSr2. SSR markers linked to Lr74 mapped within the QTL region on 3BS. SNP markers on 3BS can be used to add the Caldwell leaf rust resistance to wheat breeding germplasm.